This is a proposal to the National Institute of Health for continued support of the MIT Laser Biomedical Research Center (LBRC), a research resource center in laser biomedicine established in October, 1985 through the NIH Biomedical Research Technology Program. New and continuing activities are proposed in five categories: [1] core research and development will occur in (a) optical histochemistry, techniques and instrumentation; such studies include laser induced fluorescence and vibrational spectroscopy of tissue for new diagnostic methods of disease without biopsy; (b) molecular mechanisms of tissue alteration, techniques and instrumentation; this area includes development of new laser systems for use with optical fibers for microsurgery and for a basic understanding of ablation processes. and (c) biophysics of polymer conformations and dynamics; work includes Raman and vibrational spectroscopy of new phases in gels, picosecond and femtosecond dynamics optico-ultrasonic tomography and other areas. [2] collaborative research will occur in all of the above areas; [3] projects of outside researchers will continue to be supported using existing and new facilities and staff; [4] training and education will continue to be provided through hands-on laboratory experience, seminars and intensive one-day workshop-minicourse programs; [5] dissemination of information will continue through our publication, "The Spectrograph", and other reports. Several laboratories for medical research will be substantially expanded. These new facilities, together with the existing LBRC resources, will be available to collaborative and outside researchers.